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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,693 records · Page 94
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Method and system employing graphical electric load categorization to identify one of a plurality of different electric load types

A system for different electric loads includes sensors structured to sense voltage and current signals for each of the different electric loads; a hierarchical load feature database having a plurality of layers, with one of the layers including a plurality of different load categories; and a processor. The processor acquires voltage and current waveforms from the sensors for a corresponding one of the different electric loads; maps a voltage-current trajectory to a grid including a plurality of cells, each of which is assigned a binary value of zero or one; extracts a plurality of different features from the mapped grid of cells as a graphical signature of the corresponding one of the different electric loads; derives a category of the corresponding one of the different electric loads from the database; and identifies one of a plurality of different electric load types for the corresponding one of the different electric loads.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2015

Studies of EMP generation using a Lienard-Wiechert formulation, and progress toward a 3-D EMP code

Here, we describe studies of the generation of electro-magnetic pulse (EMP) fields under the idealized conditions of a delta-function gamma pulse, a spherical cap of Compton electrons located at a common radius from the burst, and the absence of the conduction current. Various processes (geomagnetic rotation, drag, and scattering) contribute to the time derivative of the Compton current density, which appears as the source term in the Lienard–Wiechert expression for the radiation field. These processes are considered separately and in combination, and their influences on the waveform of the EMP assessed. Using a separate computational approach, different numerical models of multiple scattering are tested, in an effort to assess the validity of existing codes and earlier results. We also describe plans for and progress toward a comprehensive 3-D EMP code, which is to employ recently developed numerical methods and is to offer a variety of models, including the Lienard–Wiechert formulation described here.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2017

Inverter communications using output signal

Technologies for communicating information from an inverter configured for the conversion of direct current (DC) power generated from an alternative source to alternating current (AC) power are disclosed. The technologies include determining information to be transmitted from the inverter over a power line cable connected to the inverter and controlling the operation of an output converter of the inverter as a function of the information to be transmitted to cause the output converter to generate an output waveform having the information modulated thereon.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2016

An Underlay Communication Channel for 5G Cognitive Mesh Networks: Packet Design, Implementation, Analysis, and Experimental Results

This paper proposes and presents the design and implementation of an underlay communication channel (UCC) for 5G cognitive mesh networks. The UCC builds its waveform based on filter bank multicarrier spread spectrum (FB-MCSS) signaling. The use of this novel spread spectrum signaling allows the device-to-device (D2D) user equipments (UEs) to communicate at a level well below noise temperature and hence, minimize taxation on macro-cell/small-cell base stations and their UEs in 5G wireless systems. Moreover, the use of filter banks allows us to avoid those portions of the spectrum that are in use by macro-cell and small-cell users. Hence, both D2D-to-cellular and cellular-to-D2D interference will be very close to none. We propose a specific packet for UCC and develop algorithms for packet detection, timing acquisition and tracking, as well as channel estimation and equalization. We also present the detail of an implementation of the proposed transceiver on a software radio platform and compare our experimental results with those from a theoretical analysis of our packet detection algorithm.

cognitive networks↗
DOE OSTI2017

New controller for high voltage converter modulator at spallation neutron source

The Spallation Neutron Source (SNS) has developed a new control system for the High Voltage Convertor Modulator (HVCM) at the SNS to replace the original control system which is approaching obsolescence. The original system was based on controllers for similar high voltage systems that were already in use [1]. The new controller, based on National Instruments PXI/FlexRIO Field Programmable Gate Array (FPGA) platform, offers enhancements such as modular construction, flexibility and non-proprietary software. The new controller also provides new capabilities like various methods for modulator pulse flattening, waveform capture, and first fault detection. This paper will discuss the design of the system, including the human machine interface, based on lessons learned at the SNS and other projects. It will also discuss performance and other issues related to its operation in an accelerator facility which requires high availability. To date, 73% of the operational HVCMs have been upgraded to with the new controller, and the remainder are scheduled for completion by mid-2017.

Wezensky, Mark W↗
DOE OSTI2017

Method and device for ion mobility separations

Methods and devices for ion separations or manipulations in gas phase are disclosed. The device includes a single non-planar surface. Arrays of electrodes are coupled to the surface. A combination of RF and DC voltages are applied to the arrays of electrodes to create confining and driving fields that move ions through the device. The DC voltages are static DC voltages or time-dependent DC potentials or waveforms.

47 OTHER INSTRUMENTATION↗
DOE OSTI2013

Performance of Ferrite Vector Modulators in the LLRF System of the Fermilab HINS 6-Cavity Test

The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton Hsup>- linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

Coda Calibration Tool

CCT is a Java based application for calibrating 10 shear wave coda measurement models to observed data using a much smaller set of reference moment magnitudes (MWs) calculated from other means (waveform modeling, etc.). These calibrated measurement models can then be used in other tools to generate coda moment magnitude measurements, source spectra, estimated stress drop, and other useful measurements for any additional events and any new data collected in the calibrated region.

Addair, Travis↗
DOE OSTI2018

New Fast Kicker Results from the Muon g-2 E-989 Experiment at Fermilab

We describe the installation, commissioning, and char-acterization of the injection kicker system for the E-989 experiment at Fermilab for a precision measurement of the muon anomalous magnetic moment. Control and monitoring systems have been implemented to acquire and record the waveforms of each kicker pulse, and measurements of various kicker system observables were recorded in the presence of the 1.45 T g-2 storage ring magnetic field. These monitoring systems are necessary to understand the systematic contribution to the measure-ment of the precession frequency. We examine the dependence of muon capture to kicker field predictions.

43 PARTICLE ACCELERATORS↗
DOE OSTI2018

On Estimating the Output Signal of the Main Drift Chamber of BES

The BES-Beijing Spectrometer1 Introduction will 94305 be a general purpose detector, working on the Beijing Electron Positron Collider. is a large cylindrical drift chamber-main One of its important drift constituents chamber which will be used to measure the tracks, momentum and energy loss dE/dz of the charged particles from collisions. The design of the drift chamber, especially its electronics read- out system, requires understanding in advance of the characteristics of the output signal of the chamber, such as the amplitude, the charge, the waveform, the count rate, etc., in order to get the best results from the time and charge measurements.

Wang, J.↗
DOE OSTI2018

Towards Measuring Longitudinal Electron Diffusion in the MicroBooNE LArTPC

MicroBooNE Liquid Argon Time Projection Chamber (LArTPC) Neutrino interactions reconstructed based on ionization electrons and scintillation light Primary goals: Investigate MiniBooNE low-energy excess Neutrino-argon cross-sections LArTPC Electron Diffusion Simulation and Selection Waveform Averaging Extraction of D L Challenges and Future Work

43 PARTICLE ACCELERATORS↗
DOE OSTI2018

New Fast Kicker Results from the Muon g-2 E-989 Experiment at Fermilab

We describe the installation, commissioning, and characterization of the injection kicker system for the E-989 experiment at Fermilab for a precision measurement of the muon anomalous magnetic moment. Control and monitoring systems have been implemented to acquire and record the waveforms of each kicker pulse, and measurements of various kicker system observables were recorded in the presence of the 1.45 T g-2 storage ring magnetic field. These monitoring systems are necessary to understand the systematic contribution to the measurement of the precession frequency. We examine the dependence of muon capture to kicker field predictions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

System and method for optimizing fundamental frequency modulation for a cascaded multilevel inverter

A system and a method for optimizing fundamental frequency modulation in a cascaded multilevel inverter (CMI) are provided. The CMI includes at least a first H-bridge module and a second H-bridge module connected in series with the first H-bridge module. The first H-bridge module is operated according to a first duty cycle and the second H-bridge module is operated according to a second duty cycle. The first duty cycle is greater than the second duty cycle. The first and second H-bridge modules are controlled utilizing fundamental frequency modulation. A portion of the first duty cycle is transferred to the second duty cycle thereby optimizing fundamental frequency modulation by at least improving power sharing between the first and second H-bridge modules and improving equalization of DC capacitor currents and voltage ripples while maintaining the same fundamental modulation to the output voltage waveform.

42 ENGINEERING↗
DOE OSTI2016

An Underlay Control Channel for Dynamic Spectrum Access: Packet Design, Implementation, Analysis, and Evaluation

This paper presents the design and implementation of an underlay control channel (UCC) that has recently been proposed for application in cognitive radio networks. The UCC builds its waveform based on filter bank multicarrier spread spectrum (FB-MC-SS) signaling. The use of spread spectrum signaling allows one to transmit UCC at a level well below noise temperature and hence, minimize taxation on the primary users. Moreover, the use of filter banks allows us to avoid those portions of the spectrum that are in use by the primary nodes. Hence, the UCC interference to the primary network will be very close to none. We propose a specific packet for UCC and develop algorithms for packet detection, timing acquisition and tracking, as well as channel estimation and equalization. We also present analytical equations that quantify the probability of false detection (when background noise is picked as a UCC packet) and the probability of missed detection (when a packet exists, but the receiver fails to detect it). Moreover, we present the detail of an implementation of the proposed transceiver on a software radio platform and compare our theoretical results with those from experiments.

42 ENGINEERING↗
DOE OSTI2018

Scanning method for screening of electronic devices

A visualization method for screening electronic devices is provided. In accordance with the disclosed method, a probe is applied to a grid of multiple points on the circuit, and an output produced by the circuit in response to the stimulus waveform is monitored for each of multiple grid points where the probe is applied. A power spectrum analysis (PSA) produces a power spectrum amplitude, in each of one or more frequency bins, on the monitored output for each of the multiple grid points. The PSA provides a respective pixel value for each of the multiple grid points. An image is displayed, in which image portions representing the multiple grid points are displayed with the respective pixel values.

47 OTHER INSTRUMENTATION↗
DOE OSTI2019

Quantification of the systematic uncertainties associated with measuring a chance coincidence background at Chi-Nu

Modern advances in waveform digitizers allow coincidence experiments to be performed by recording singles data, and identifying coincidences in a later software analysis. It has been previously shown that for such data, the coincidence background can be obtained with unprecedented statistical precision. This method is especially attractive for experiments with complicated, time-varying backgrounds (i.e. not amenable to analytic or even a detailed Monte Carlo analysis). Many neutron detection experiments fall into this category, such as the Chi-Nu experiment to measure the prompt fission neutron spectra of the major actinides. While it is believed that use of this method will yield an improved systematic precision of the measured background, this has not previously been demonstrated. Presented here is the first analysis of the systematic uncertainties associated with this method

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2019

Silicon Photomultiplier for Medical Imaging -Analysis of SiPM characteristics-

This paper proposes an automatic procedure, based on ROOT data Analysis Framework, for the analysis of Silicon Photomultipliers (SiPM) characteristics. In particular, it can be used to analyze experimental waveforms, from oscilloscope, containing SiPM pulses acquired at different temperatures and bias voltages. Important SiPMs characteristics such as: charge distribution, gain, breakdown voltage, pulse shape (rise time and recovery time) and overvoltage can been calculated. Developed procedure can be easily used to analyze any type of SiPM detectors.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

3D PRINTED LAYER OF POLYANILINE-BASED CONDUCTIVE POLYMER FOR LIGHTNING STRIKE PROTECTION OF CFRPS

Manufacturing of Carbon Fiber Reinforced Plastics (CFRPs) using additive manufacturing (AM), or 3D printing, has gained popularity in recent years. It is believed that the AM industry has the potential to manufacture CFRP parts in a faster, easier and more economical way. Lightning strike damage to CFRP parts is not rare; therefore, additional lightning strike protection (LSP) technologies are applied on top of CFRP structures. However, there is no report of manufacturing lightning strike protection (LSP) technologies using the AM process. In the present work, the authors applied an electrically conductive layer via additive manufacturing. The material of the electrically conductive layer was a Polyaniline (PANI)-filled thermoset composite. This layer of PANI was deposited on top of the CFRP panels. The PANI-coated CFRP panels were tested against a simulated lightning strike made of a continuous waveform with component A (100 kA), component B (2 kA) and component C (470 A). The highly conductive PANI-layer worked as a capable Faraday cage to safely dissipate the lightning current. In PANI-based LSP, direct contact between PANI chains dominated the conduction behavior, which proved to be a highly efficient way to reduce resistive heating from the incident current. However, poor adhesion between the printed layer and the substrate structure needs to be improved in the future. The results from the thermal camera and the high-speed camera images showed an effective current dissipation through the printed layers. Non-destructive ultrasonic imaging was done to confirm the direct lightning damages to samples. The present work shows that a non-metallic conductive layer can be applied as an LSP of CFRP structures via an additive manufacturing technique.

Kumar, Vipin↗